I know this is AIBU but I’ve posted on the baking board with no response and I know the traffic here is immense.... so;
Can I ask: I’ve baked some cupcakes for my daughter’s birthday tomorrow (to take to school) we leave the house at 730am so no time in the morning to make buttercream and no time to take it out of the refrigerator to let it come to room temp and rewhip. Can I ice with buttercream tonight and lock it in an airtight container? Overnight? Will the buttercream go bad/crusty?
I've done that before. It won't go crusty for one night. In fact, I've covered a cake in buttercream a day and a half in advance and it's been fine. Just take them out of the fridge when you wake up so that they can come to room temperature.